Synthesis and characterization of transitional metal-rich zeolite M-MFI (M = Fe, Co, Ni, Cu) with regular mesoporous channels

Transitional metal-rich zeolites M-MFI (M = Fe, Co, Ni, Cu) with uniform pore channels are synthesized by a novel route in relatively mild condition. In this method, ionic complex as the structure-directing agent could directly introduce the transitional metal into zeolite. These samples are characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), N2 adsorption–desorption, H2-temperature program reduction (H2-TPR), Fourier transformed infrared spectroscopy (FT-IR), X-ray absorption fine structure (XAFS) and thermogravimetry-differential scanning calorimetry (TG-DSC). The results show that this kind of transitional metal-rich zeolites fall into the category of the orthorhombic system and possess high thermal and hydrothermal stability, large surface area, mesoporous channels (3.3–3.8 nm) and narrow size distribution. Meanwhile, with the different electronic configuration and ionic radii of transition metal, a large amount of the iron and cobalt species are introduced into the framework while the nickel atoms are interacted with the interface of pore channels and cooper atoms exist as the metal-cluster within the pore channels.